Generally, an image forming apparatus conveys a sheet by a roller. The roller wears during the use. Conventionally, a replacement time of the roller is determined based on the number of sheets subjected to image formation. However, as there are various sizes of the sheets conveyed by the roller, the amount of wear of the roller caused by conveyance of one sheet with different size is different. Furthermore, even at the time the image forming apparatus does not convey a sheet (e.g., during a warm-up operation), the roller rotates and wears in some cases. Therefore, in the determination based on the number of sheets on which the image formation is performed, there is a case in which the replacement time of the roller is not necessarily an appropriate timing.